2024-04-10から1日間の記事一覧
本日も前回の用法の続きです。 ・There is a perfectly well-established method of working coal which entails planned collapses. The first lot of coal is worked out leaving huge pillars holding the roof up. Then with the excavated portions sup…
本日も前回の用法の続きです。 ・There is a perfectly well-established method of working coal which entails planned collapses. The first lot of coal is worked out leaving huge pillars holding the roof up. Then with the excavated portions sup…